Nervous System
Organs & Divisions
Central Nervous System: CNS=brain
and spinal cord
Peripheral Nervous System: PNS=
all nerves
Autonomic Nervous System:
ANS=automatic responses
Central Nervous System
Brain & Spinal Cord
Divisions of the Brain
Brainstem: Medulla Oblongata, Pons,
Midbrain
Cerebellum
Diencephalon: Hypothalmus, Thalmus
Cerebrum
Brainstem:
Lies just above the
spinal cord in the
following order:
Medulla
oblangata:cardiac,
respiratory and
vasomotor control
Pons: influences
respirations
Midbrain: relay for
visual and auditory
impulses
Brain…labeled
Diencephalon
Thalmus: responsible for sensations,
associates sensations with
emotions,(pleasantness, unpleasantness), and
arousal or alerting mechanism
Hypothalmus:helps regulate hormones,
body temperature, water balance, sleep
cycles, control of appetite and many emotions
involved in fear, anger, pleasure, sexual
arousal and pain. Controls vital functions:
heartbeat, constriction & dilation of blood
vessels, and contractions of stomach &
intestines
Cerebellum
Produces smooth coordinated
movements, maintain equillibrium, and
sustain normal postures
Cerebrum
Largest portion of the brain,
Convolutions(ridges) called gyri.
Grooves called sulci.
Deep sulci are called fissures.
Divided into 4 major lobes: Frontal, Parietal,
Temporal, Occipital
Subdivided according to function. Spinal Cord
Lies in the vertebral foramen of the vertebra.
Extends from the occipital bone to just above
the 4th lumbar vertebrae.
Provides 2 way conduction paths to and from
the brain.
CNS
ACTUAL
HUMAN
CNS
PNS
Spinal Cord
Reflexes: jerk reflexes and withdrawal
Sends impulses to the brain. Sensory
impulses travel up to the brain in
ascending tracts, and motor impulses
travel down the cord in descending
tracts.
Injury to the cord transversely results in
loss of function, therefore particular
anatomical functions are lost. Ex:
paralysis.
Cross Section Spinal cord
Cervical Section of
Spinal cord
Lumbar section of
Spinal cord
The Meninges
Tough fluid containing membrane
Spinal meninges form a tubelike
covering around the spinal cord and line
the vertebral foramen.
3 layer: Innermost: Pia Mater;
Middle layer: Arachnoid;
Outermost: Dura Mater
Meningitis=infection or inflammation
Bacterial vs. Viral/Aseptic
Bacterial: most commonly caused by
Neisseria meningitidis (meningococcus),
Streptococcus pneumoniae, or Haemophilis
influenzae Treatable with antibiotics
Viral/Aseptic: various causes, no specific
treatment: usually resolves in 10 days:less
deadly
www.cdc.gov
Meningitis
S/S: severe
headache, nucal
rigidity, (neck
stiffness)
Fever, vomiting
*SEEK MEDICAL
HELP IMMEDIATELY*
Can be mild and self
limiting, to fatal.
Diagnosed by spinal tap
Cerebrospinal Fluid (CSF)
Flows in between the Pia mater and
Arachnoid mater, (Subarachnoid space)
as well as ventricles of the brain
Formed in the Choroid Plexus.
(network of brain capillaries) and in the
ventricles of the brain.
End H/S
12 Cranial Nerves…Oh Oh Oh To Touch
And Feel Very Good Velvet Auburn Hair
Mnemonic device to remember….